Project Summary Amid long standing improvements in life expectancy and infant mortality in the United States, a discordant new trend has emerged -- maternal mortality and morbidity are on the rise. Concurrent with this trend is evidence of racial disparities, particularly among non-Hispanic black women, who are experiencing these adverse outcomes at much higher rates than other groups. These phenomena are only beginning to be studied and understood by researchers. The medical causes of maternal mortality and morbidity are easily identified, but an explanation of the underlying reasons is lacking. In previous studies that document trends in maternal mortality and morbidity, researchers have hypothesized that factors contributing to these trends include older maternal age, increased body weight, cigarette and illegal drug use during pregnancy, low SES, and issues related to providers and medical care. However, we currently have little guidance from the literature on which factors are the most influential or where policy interventions can be most beneficial. The purpose of this proposed research is twofold. The first goal is to conduct an exploratory analysis of the determinants of maternal mortality and morbidity in an effort to identify the factors that may or may not contribute to the underlying causes. We group potential explanatory variables into maternal characteristics, hospital characteristics, variables reflecting access to care, and community-level measures of the socioeconomic environment. The second objective is to investigate the sources of racial disparities in maternal mortality and morbidity. To accomplish these aims, we will first generate rates of maternal morbidity and mortality for 1998-2011 using the Nationwide Inpatient Sample (NIS). We will combine this data with additional information from the patient, hospital, and the larger community (the county). We will estimate the contributions of the different variables and variable groups to the overall variation in morbidity and mortality rates across hospitals and within hospitals over time. We will then use regression-based re-weighting techniques to examine the sources of racial disparities. Our results will provide guidance on what types of variables would benefit from further study. Once these are identified, future research can focus on evaluating different public policies as potential solutions to reduce maternal morbidity and mortality.